1. Field of the Invention
This invention relates to a new class of copolymers of chloral with at least one isocyanate, isothiocyanate, diisocyanate, diisothiocyanate or ketene and process for their preparation.
2. Description of Prior Art
Applicant's U.S. Pat. No. 3,454,527 issued July 8, 1969, discloses homopolymers of chloral prepared by a process which involves preparing a uniform mixture of chloral and polymerization initiator at a temperature above the threshold polymerization temperature of the mixture, cooling the uniform mixture below the threshold polymerization temperature, and maintaining the mixture quiescent during the polymerization.
U.S. Pat. No. 3,265,665 issued to Mantell et al. on Aug. 9, 1966 discloses copolymers of formaldehyde and isocyanates by a polymerization process which involves cooling to low temperatures. Chloral is not disclosed nor suggested and quiescent conditions are not maintained during the polymerization process.
Takida et al, Kobunski Kagaku [Chemistry of High Polymers, Japan] 22, 463-472, July 1965, show the copolymerization of chloral with phenyl isocyanate at low temperatures but do not use quiescent polymerization conditions. Their process produced only crumbly, powdery products.